The long-term objective is to produce a system to measure vocal performance from the acoustic waveform of normal and pathological subjects. This system must be flexible enough to handle existing as well as future metrics that may prove useful. Most importantly, it must be "user-friendly" so that researchers and clinicians can easily use it. Specific aims in Phase I are to prove the technical feasibility of accomplishing this objective. This requires demonstrating that a system of sufficient accuracy and resolution can automatically detect and track the fundamental frequency of vibration of the vocal folds (FO), overthe entire range of FO possible, reliably and with no operator adjustment required. It is expected that this will be demonstrated in Phase I. The development of the system will be pursued in Phase II. There are two different commercial applications. The first is for a sophisticated research tool to enable additional clinical investigators to effectively and easily conduct the fundamental research that is still needed on vocal pathology. The second is a simpler system (and less expensive) for use by practicing professionals (otolaryngologists, other M.D.s, speech pathologists and therapists, hospitals, and possibly schools). This will allow a quantitative measure of vocal performance, currently lacking, that can be of value in longitudinal studies, in detecting pathologies and in providing a benchmark of performance in evaluating therapeutic effectiveness.